REVIEWS 501 



The Evolution of Continuity in the Natural World. By David Russell, 

 M.D., Director of the British Hospital, and Doctor to the British Lega- 

 tion, Lisbon. [Pp. vi + 278, with 3 illustrations.] (London : George 

 Allen & Unwin. Price 165. net.) 



We hesitate to say whether the doctor has been wise to venture from the 

 hospital portals into the treacherous sands of biological philosophy. To the 

 ordinary zoologist this book will seem strange, and, to be candid, difficult to 

 understand. The author begins his book with the aid of two glass beads on 

 a tray at a little distance from each other. By means of these glass beads 

 he explains the plot : the beads on the tray are in a state of Discontinuity — 

 but by bringing the beads together this Discontinuity is changed to Con- 

 tinuity. " The evolution of Living Continuity, whose attempted demon- 

 stration is the main object of this book, is only one aspect of an evolution of 

 Continuity, ' ' etc . ' ' Matter owes its existence to the institution of Continuity. ' ' 

 Again: "Man can produce endless systems of Continuity higher than the 

 molecular ; for example, he can make a large number of bricks ; can unite 

 them together to form a house ; can make a number of similar houses joined 

 together in a row," etc. 



This is not a description of a colliery village, or of Pimlico — as one might 

 think at first. At any rate, the author dogmatises on every question from the 

 peculiar behaviour of the two glass beads, to the Evolution of Matter, and 

 again to the Origin of Species and the Cause of Cancer. 



Seriously, we cannot deal with this book much further. The author's 

 chapter on Karyokinesis, for example, is pure rubbish from beginning to end : 

 he is unacquainted with the literature of the subject. The other chapters 

 are equally useleso, and the book simply bristles with statements which would 

 only be made by one whose knowledge of modern biology is extremely 

 curtailed. We are sorry thus to speak of the work of the author, but we are 

 unable to understand why the book came to be published. 



J. Bronte Gatenby. 



A Textbook of Zoology. By the late T. Jeffery Parker, D.Sc, F.R.S., 

 and William A. Haswell, M.A., D.Sc, F.R.S. [Vol. I, pp. xl + 

 816, with 713 figures; Vol. II, pp. xx + 714, with 503 figures.] (London: 

 Macmillan & Co. Price 505. net.) 



This is the third edition of this splendid work. It has been revised by Prof. 

 Haswell, with much help from Prof. W. N. Parker, who had already been 

 identified with the two earlier editions. 



The Nemathelminthes, Molluscoida, and the Annulata have been especially 

 revised. There can be no doubt that in those Universities where the Final 

 Examination is constituted by two subjects such as Zoology and Botany, 

 these two volumes by Parker and Haswell make a very convenient textbook. 

 Eked out with special professorial lectures and good practical classes, Parker 

 and Haswell's book would be a most suitable basis for the student. 



The articles at the end of the second volume are very good. The work 

 needs no recommendation from us. 



J. Bronte Gatenby. 



Birds One should know. Beneficial and Mischievous. By the Rev. Canon 

 Theodore Wood. [Pp. xi -f 132, with numerous coloured and 

 uncoloured illustrations, by Roland Green, F.Z.S.] (London: Gay 

 & Hancock, 1921. Price 105. 6d. net.) 



The main purpose of the brief text accompanying the illustrations of the 

 33 species with which the author deals is to indicate their value to the agri- 

 culturist and horticulturist. This is achieved in a pleasing and simple 

 manner. It is a matter of regret that the author does not cite his authority 



